Refrigerant flow controlling means



Dec. 16, 1947. F. Y. CARTER REFRIGERANT FLOW CONTROLLING MEANS FiledApril 10, 1944 IN VEN TOR.

Y E N m T T A 5 H Patented Dec. 16, 1947 2,432,859 REFRIGERANT FLOWCONTROLLING MEANS Franklyn Y. Carter, Detroit, Mich., assignor toDetroit Lubricator Company, Detroit, Mich., a corporation of MichiganApplication April 10, 1944, Serial No. 530,263

8 Claims.

This application relates to new and useful improvements in refrigeratingapparatus, and more particularly to a system having a multi-passevaporator and means for supplying refrigerant thereto.

An object of the invention is to provide a novel refrigerant distributorwhich will feed refrigerant equally to each of the passes or tubes ofthe evaporator.

Another object is to provide a distributor in which the probability offeeding any vaporized refrigerant to the distributor orifices is reducedtoaminimum.

Another object is to provide means for accurately metering the flow ofrefrigerant'to a multi-pass evaporator so as to maintain the samerefrigerated to a substantially fixed extent during compressoroperation,

Another object is to provide a photo-electric control forthe feeding ofrefrigerant to the evaporator.

The invention consists in the improved construction and combination ofparts and their cooperative relation to be more fully describedhereinafter and the novelty of which willbe particularly pointed out anddistinctly claimed.

In the accompanying drawings to be taken as a part of thisspecification, there arefully and clearly illustrated several preferredembodiments of the invention, in which drawings:

Figure 1 is a diagrammatic view of a refrigerating apparatus showing theelectrically controlled refrigerant distributor in longitudinal verticalsection and showing the wiring diagram for the photocell control of thedistributor, and

Fig. 2 is a diagrammatic view of part of the refrigerating apparatus ofFig, 1 but showing differential temperature responsive means forcontrolling the distributor.

In the accompanying drawings to be taken as a part of thisspecification, there are fully and clearly illustrated several preferredembodiments of the invention, in which drawings:

Figure 1 is a diagrammatic view of a refrigerating apparatus showing theelectrically controlled refrigerant distributor in longitudinal verticalsection and showing the wiring diagram for the photocell control of thedistributor, and

Fig. 2 is a diagrammatic view of part of the refrigerating apparatus ofFig. 1 but showing differential. temperature responsive means forcontrolling the distributor.

Referring to the accompanying drawing, l designates generally a motordriven compressor having an outlet conduit 2*connected to a reirigerantcondenser 3 which feeds through a conduit 4 into a refrigerant receiver5 from which a liquid line or conduit 8 connects to the inlet passageway1 of the electric distributor 8. The

5 bottom wall of the distributor 8 is formed by a closure plate ormember 9 having a plurality of passageways l0 therethrough equal innumber to the passes or tubes of the evaporator to be supplied withrefrigerant. Each of the passageways ID has secured and sealed therein acapillary refrigerant feeding tube H which has its other end connectedto the inlet of one of the tubes or passes l2 ofthe multi-tubeevaporator 13, having the usual suction header l4.' The inlet of thecompressor I is connected to the suction header by a suction conduit [5having intercalculated thereina light transmitting or bullseye portionl6 for the passage of a light beam therethrough from a light source I!which may be the usual electric lighting device forming part of aphoto-electric control system.

The distributor 8 has a vertical tubular hollow housing 3 with upper andlower end flanges I9, 20 respectively. Adjacent the upper' end of thehousing member l8 there is an internal horizontal partition 2| whichdivides the housing member into an upper liquid inlet chamber 22 and alower refrigerant feeding chamber 23. The inlet passageway 1 openslaterally into the chamber 22 which is communicatively connected to thechamber 23 by a valve port 24 in and extending vertically through thecentral portion of the partition 2|. The top of the chamber 22 is closedand sealed by a casing 25 which is clamped by bolts 26Ito the flange l9.Within the casing 25 there is an electro-magnctic coil 21 surrounding atubular guide member 28 in which there is reciprocally positioned thestem 29 of a valve member 30 cooperable with the port 24 to control flowtherethrough. The valve member 30 carries an armature 3| for cooperationwith the coil 21 to open the valve member 30. A light coil spring 32 maybe provided within the guide member 28' to urge the valve member towardclosed position. The bottom closure member 9 preferably has av flange 33between which and the flange 20 a sealing gasket or the like 34 may beclamped by bolts 35. The chamber face of the closure member 9 isprovided with a cylindrical recess 36"to receive an orifice plate 31having calibrated orifices 38 there through equal in number to theoutlet passageways lll and registering therewith. The side pertions ofthe recess 36 extend laterally outward to beneath the wall of thehousing member I8 so that the plate 3! will be tightly clamped by thebolts 35 in position betweenthe closure member 9 and the housing memberI8.

Each of thetubes II and its restricting orifice 38 has a predeterminedresistance to refrigerant flow for a given compressor suction pressureand a given refrigerant pressure in the feeding chamber 23 for a givenload on the evaporator I3. The valve port 24 is therefore madesufficiently large so that in the wide open position of the valve member30, the effective flow area through the port 24 will cause a minimumdrop of pressure from the liquid head pressure in theinlet chamber 22and the pressure in the feeding chamber 23. By reason of thepredetermined restriction to flow afforded by the orifices 38 and tubesII, the pressure drop across the port 24 may be restricted to severalpounds so that the pressure drop across the port 24 will not lower thepressure below or appreciably below a pressure corresponding to thesaturation temperature of the liquid refrigerant supplied to the inletchamber 22. The condenser 3, as is common in the refrigeration art, willcool the refrigerant somewhat below its saturation temperature as afactor of safety to eliminate gasifying of the refrigerant during itsflow or passage through the liquid supply line 6. It is this usualcooling of the refrigerant below its saturation temperature which makespossible the discharge into the feeding chamber 28 of liquid refrigerantwith little or no vaporization due to the small pressure drop throughthe valve port 24. The effective flow area of the port 24 is greaterthan the combined flow areas of the orifices 38 so that substantiallyinstantaneously with the opening of the quickly acting valve member 30,the feeding chamber 23 will be filled solid with liquid refrigerant andno vaporization of the liquid refrigerant in the chamber 23 will occur.The size or volumetric capacity of the chamber 23 is sufiiciently largeso that during operation of the compressor I there will always be liquidrefrigerant overlying the orifices 38 with the result that liquidrefrigerant will be fed to the feeding tubes II and therefore therefrigerant will be equally and uniformly distributed to each of thepasses or tubes I2 of the evaporator I 3.

The valve member 30 is controlled by the magnet coil 21 which is in turncontrolled by a relay switch 39 having its relay coil 40 in theelectrical network of a photocell system including the light source II.The light beam indicated by the dash dot line H from the source I1shines through the transparent suction conduit section I6 and when notrefracted by liquid refrigerant, the light beam passes through anaperture 42 in a. shield or box 43 containing a photo-electric cell 44and impinges upon the cathode 45. Energization of the cell 44 bythelight shining upon the cathode 44 renders the control grid 45 of theelectron tube 41 sufllciently positive so that current flow through thetube 41 will occur, thereby energizing the relay coil 40 to close theswitch 39 and open the valve member 30. The electrical network includingthe relay coil 40, tube 41 and cell 44 may be any of the well knownsystems supplied with alternating current from the usual line voltagetransformer 48 and therefore a detailed description of the network isnot necessary to a full understanding of this invention. When liquidrefrigerant enters the transparent conduit section I6 and refracts thelight beam 4I so that it fails to pass through the shield aperture 42,then the electron tube 41 will be deenergized the liquid refrigerantintercepts the 4 and the switch 39 will open so that the valve 30 willmove quickly to closed position under the force of gravity and spring32.

The operation of the refrigeration system of Fig. 1 will be apparentfrom the foregoing, al though it may be noted that the system isparticularly adapted for use in air conditioning or the like where theload on the evaporator I3 will be maintained substantially constant. Atthe beginning of a cycle of compressor operation the liquid refrigerantline will have receded toward the header I4 from the conduit section I6so that the valve 30 will be open and refrigerant will be supplied tothe feeding chamber 23 and thence to the evaporator tubes I2. As soon aslight beam 4| sufiiciently to deenergize the cell 44, then the valve 30will close as above noted. Intermittent opening and closing of the valve30 will then continue during the compressor operation so that liquidrefrigerant will be maintained in the feeding chamber 23 and theevaporator I3 will be refrigerated throughout its length.

Referring to Fig. 2 the electric distributor 8 is controlled by adifferential switch 50 having volatile liquid power elements 5I, 52 withtemperature responsive bulb elements 53, 54 respectively. The powerelements 5| and 52 operate to close the switch 50 whenever thedifference between their respective temperatures exceeds a predeterminedamount, the switch closure energizing the distributor coil 21 so thatliquid refrigerant is supplied to the feeding chamber 23 and thence tothe evaporator I3. The bulb 53 is clamped to one of the evaporator tubesI2 adlacent its inlet end and the bulb element 54 is clamped to thesuction line I5 so that irrespective of the temperature range to whichthe bulb elements 53 and 54 are subjected, they will function to controlthe switch solely in accordance with the differential between theirtemperatures and accordingly will maintain the evaporator I3 completelyrefrigerated during the compressor operating cycle. The operation of thesystem of Fig. 1 with the control switch 50 will be apparent from theforegoing description.

Having thus described my invention, what is claimed and is desired to besecured by Letters Patent of the United States is:

1. In a refrigerating apparatus a multi-tube evaporator having a suctionheader, a tubular vertical housing member, a horizontal partitiondividing said housing member internally into an upper inlet chamber anda lower liquid feeding chamber, said partition having a valve port, acasing on the upper end of said housing member, an electro-magnetic coilin said casing, a valve member in said inlet chamber and movable toclose and to open said port and having an armature cooperable with saidcoil, a bottom Wall closing the bottom end of said feeding chamber andhaving a plurality of passageways therethrough leading from said feedingchamber, each of said passageways having a calibrated orifice portion,said port having an effective flow area when said valve member is openwhich is greater than the combinedfiow areas of said orifice portionsthereby to maintain liquid refrigerant in said feeding chamber, saidhousing member having an inlet passageway to said inlet chamber,refrigerant feeding tubes connecting said bottom wall passageways to thetubes of said evaporator,

and switch means responsive to the extent of refrigeration of saidevaporator and controlling said electro-magnetic coil.

2. In a refrigerating apparatus a multi-tube evaporator having a suctionheader, a tubular vertical housing member, a horizontal partitiondividing said housing member internally into an upper inlet chamber anda lower liquid feeding chamber, said partition having a valve port, acasing on the upper end of said housing member, an electro-magneticcoilin said casing, a valve member in said inlet chamber and movable toclose and to open said port and having an armature cooperable with saidcoil, a bottom wall closing the bottom end of said feeding chamber andhaving a plurality of passageways therethrough leading from said feedingchamber, each of said passageways having a calibrated orifice portion,said port having an effective flow area when said valve member is openwhich is greater than the combined flow areas of said orifice portionsthereby to maintain liquid refrigerantin said feeding chamber. saidhousing member having an inlet passageway to-said inlet chamber,refrigerant feeding tubes connecting said bottom wall passageways to thetubes of said evaporator, a relay switch controlling saidelectro-magnetic coil, a suction conduit connected to said header, andphoto-electric controlling means responsive to predetermined flow ofliquid refrigerant into said suction conduit and controlling said relayswitch.

'3. In a refrigerating apparatus, a plurality of refrigerant evaporatingmembers, a common suction line leading from said members, a housingmember 'having an inlet chamber with an inlet for admission of liquidrefrigerant and having a liquid feeding chamber communicating with saidinlet chamber through a valve port, a valve member controlling said portand having open and closed positions, electrically operable means to.

move said valve member quickly from and to said positions, said housingmember having a plurality of passageways leading from the bottom of saidfeeding chamber, each of said passageways having a calibrated orificeportion, said valve port having an effective flow area when said valvemember is in said'open position which is greater than the combined flowareas of said orifice portions thereby to maintain liquid refrigerantover said passageways and in said feeding chamber, refrigerant feedingtubes connectlng said passageways to said evaporating members, and meansresponsive to a refrigerant condition in said suction line andcontrolling the energization of said electrically operable means.

4. A liquid refrigerant distributing device, comprising a housing memberhaving an inlet chamber with an inlet for admission of liquidrefrigerant and having a liquid feeding chamber communicating with saidinlet chamber through a. valve port, a valve member controlling saidport and having openand closed positions, means to move said valvemember quickly from and to said positions, said housing member having aplurality of passageways leading from the bottom of said feedingchamber, each of said passageways having a calibrated orifice portion,said valve port having an effective flow area when said valve member isin said open position which is greater than the combined flow areas ofsaid orifice portions thereby to maintain liquid refrigerant over saidpassageways and in said feeding chamber.

5. A liquid refrigerant distributing device. comprisin a housing memberhaving an inlet chamber with an inlet for admission of liquidrefrigerant and having a liquid feeding chamber communicating with saidinlet chamber through a valve port in the top wall of said feedingchamber, a valve member controlling said port and having open and closedpositions, electrically operable means to move said valve member quicklyfrom and to said positions, said housing member having a plurality ofpassageways leading from the bottom of said feeding chamber,,each ofsaid passageways having a calibrated orifice portion, said valve porthaving an effective flow area when said valve member is in said openposition which is greater than the combined flow areas of said orificeportions thereby to maintain liquid refrigerant over said passagewaysand in said feeding chamber.

6. A liquid refrigerant distributing device, comprising a housing memberhaving an inlet chamber with an inlet for admission of liquidrefrigerant and having a liquid feeding chamber communicating with saidinlet chamber through a .valve port in the top wall of said feeding chamber, a solenoid operated valve member on the inlet side of andcooperable with said port and having only full open and full closedpositions, said housing member having a plurality of passageways leadingfrom the bottom of said feeding chamber, each of said passageways havinga calibrated orifice portion, said valve port having an effective flowarea when said valve member is in said open position which is greaterthan the combined flow areas of said orifice portions thereby tomaintain liquid refrigerant over said passageways and in said feedingchamber.

7. A liquid refrigerant distributing device, comprising a housing memberhaving an inlet chamber with an inlet for admission of liquidrefrigerant and having a liquid feeding chamber communicating with saidinlet chamber through a valve port, a valve member controlling said portand having open and closed positions, means to move said valve memberquickly from and to said positions, said feeding chamber having an openlower end, a closure member for said lower end and sealed to saidhousing member, said closure member having a. plurality of passagewaystherethrough leading from said feeding chamber, an orifice plate securedto said closure member and having calibrated orifices therethroughregistering with said passageways, said valve port having an effectiveflow area when said valve member is in said open position which isgreater than the combined flow areas of said orifice portions thereby tomaintain liquid refrigerant over said passageways and in said feedingchamber.

8. A liquid refrigerant distributing device, comprising a housing memberhaving an inlet chambez with an inlet for admission of liquid refrigernt and having a liquid feeding chamber communicating with said inletchamber through a valve port, a valve member controlling said port andhaving open and closed positions, means to move said valve memberquickly from and to said positions, said feeding chamber having an open-bottom end, a closure member clamped to said housing member and closingthe bottom end of said feeding chamber and having a recess in itschamber face, said recess extending beneath the wall of said housingmember, a plurality of passageways extending vertically through saidclosure member and leading from said recess, an orifice plate fittingsaid recess and having an edge portion underlying said housing memberwall and clamped between said housing member and said closure member,said orifice plate having calibrated orifices therethrough registering 7with said passageways, said valve port having an efiective flow areawhen said valve member is in said open position which is greater thanthe combined flow areas of said orifice portions thereby to maintainliquid refrigerant over said passageways and in said feeding chamber.

FRANK'LYN Y. CARTER.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date Berydoll May 16, 1939 RustigeMar. 30, 1920 Campbell Feb, 11, 1936 Labberton Feb. 21, 1939 RickettJuly 6, 1943 Protzei1er Sept, 8, 1931 Morton Jan. 3, 1939 Shrode J an,24, 1939 Lawrence Oct. 14, 1919 Young Mar, 10, 1925

